East Carolina University
Department of Psychology

Wuensch, K. L., Poteat, G. M., & Jernigan, L. M. (1991, June). Support for animal rights and perceived similarity between humans and other animals. Paper presented at the annual meeting of the Animal Behavior Society, Wilmington, NC.


    Over the past two decades, the number of animal rights activists in the United States has grown to an estimated two million. The primary objective of most activists is to end the use of animals in research. Tactics used by activists to bring about change include legislative action, communication campaigns, and, less commonly, vandalism of laboratories. Concerned with the rise of anti-animal research sentiment, many psychologists have begun researching the psychological factors associated with support for animal rights. A review of the outcomes of this research is presented.

    In this study, 284 college undergraduates responded to eleven questionnaire items designed to assess beliefs about the similarity between humans and nonhuman animals and attitudes towards animal rights. The majority of the participants believed that nonhuman animals are capable of thinking and experiencing emotion. Approximately half believed that humans and animals are very similar. Fifteen percent of the participants advocated equal rights between humans and animals.

    Analysis of the relationship between perceptions of human-nonhuman animal similarity and attitudes towards animal rights revealed that the belief that animals can think and experience emotion and are similar to humans is associated with positive attitudes toward animal rights. Similarity beliefs explained 17.3% of the variance in attitudes toward animal rights.


    The animal rights movement has been described as "one of the most visible and effective grassroots social movements in the United States today" (Herzog, 1990). Through organized activity, animal rights activists have had substantial impact on the public's perceptions about the way in which humans treat animals. The animal rights controversy has been featured extensively in the popular media (e.g., Cowley, 1988; Hitt, 1988; Royte, 1992; Zak, 1989). Ethical considerations regarding animals have become a public policy issue, most notably in the area of animal-based research (Grodsky, 1983).

    Jasper and Nelkin (1992) categorize animal protectionists into three groups differentiated by their beliefs about animals, major goals and primary strategies. "Welfarists" view animals as objects of compassion, make a clear distinction between human and nonhuman animals, accept most traditional practices concerning animals such as eating meat and using them as research subjects, and effect change primarily through enactment of protective legislation. The animal rights movement grew out of the animal welfare movement.

    "Pragmatists" are animal rights advocates who believe that there should be a greater balance between human and animal interests, believe that certain species deserve greater consideration than do others, and desire to eliminate all unnecessary suffering through reduction, refinement, and replacement of animals in traditional uses. Pragmatists primarily seek to achieve results through public protests tempered by pragmatic negotiation and acceptance of short-term compromises.

    The third group, the "fundamentalists," comprise the activists who "set the tone of the new animal rights movement" (p. 9). They believe that animals have absolute moral rights to conduct their lives free from interference from humans and advocate equal rights across many species. They demand the total and immediate elimination of all animal exploitation (e.g., consumption of animal food products, use of animals as research subjects, use of animals for sports and entertainment, and pet ownership). Their primary strategies include moralist rhetoric and condemnation, civil and illegal disobedience, and the establishment of sanctuaries.

History of the Movement

    The animal rights movement has its roots in public reaction to the use of live animals as research subjects by early experimental physiologists. Rene Descartes' pronouncement that animals were mere automata, incapable of feeling pain or thinking, served as the researchers' ideology and rationalized the performance of vivisection without anesthesia (Rowan & Rollin, 1983). In the mid-nineteenth century, opposition grew under the  leadership of utilitarian philosophers, principally Jeremy Bentham, who is well known by animal rightists for his statement about animals: "The question is not, Can they reason! nor Can they talk!, but Can they suffer!" (Bentham, cited in Rowan & Rollin, 1983).

    In 1824, the first animal welfare society, the Society for the Prevention of Cruelty to Animals (SPCA), was formed in England and became the Royal Society (RSPCA) in 1840 under the request of Queen Victoria (Niven, 1967). The Society for the Protection of Animals Liable to Vivisection followed in 1875, organized by RSPCA members who were dissatisfied with lack of action to end the practice of vivisection (French, 1975). Inthe following year, they successfully facilitated the passage of the Cruelty to Animals Act, which protected vertebrate animals by requiring licensing of experimenters, inspection of facilities and limited use of animals in teaching. This legislation served as the prototype for future legislation in other countries (Dewsbury, 1990).

    In the United States, the first animal welfare society was organized in 1866, and the first antivivisectionist society followed in 1883. Early antivivisectionist activity peaked in the early twentieth century with heavily publicized criticism of animal research activities, including those of psychologists, notably Watson, Pavlov, and Cannon. The American Psychological Association (APA) responded by forming its Committee on Animal Experimentation in 1925 (Dewsbury, 1990). Opposition to vivisection waned during the two World Wars due to the growth of the reputation of medical research (Rowan & Rollin, 1983).

    The modern animal rights movement began in the mid-1970's with the publishing of Peter Singer's (1975) book, Animal Liberation, widely acknowledged as the movement's bible (Jasper & Nelkin, 1992). Dewsbury (1990) attributes the rise of the modern movement to 1960's activism, enactment of civil rights for women and minorities, and the increasing concern over environmental issues.

    During the past two decades, the number of animal rights organizations and membership in these groups has grown enormously, principally in the United States (Garner, 1993). Between the mid-1970's and mid-1980's, five- to ten-fold increases in membership in animal rights organizations were common (Rowan, cited in Garner, 1993). The largest organization, the People for the Ethical Treatment of Animals (PETA), increased its membership from 20 in 1980 to 350,000 in 1990 (Lutherer & Simon, 1992).  Vaughan (1988) estimates that there are 400 animal rights organizations nationwide with two million members.

    Animal rights activists contend that animals are being exploited by humans in a variety of ways including being used unnecessarily for food, clothing, and sports and entertainment. However, the primary objective of animal rights activism is to end the use of animals in biomedical research (Nicoll & Russell, 1990; Plous, 1991). Psychologists' use of animals in behavioral research has also been targeted by activists who characterize it as being cruel (Rollin, 1981, 1985) and irrelevant (Plous, 1991).

    The campaign against animal research has been waged primarily through pamphlets displaying grisly pictures that invoke strong human emotions. Smaller underground groups such as the Animal Liberation Front and the Band of Mercy have taken more direct action by breaking into laboratories, liberating lab animals, destroying years of data, and vandalizing equipment (Vaughan, 1988). Since 1982, there have been more than 80 break-ins into research and educational institutions across the United States (Lutherer & Simon, 1992).

Reaction of the Scientific Community

    Many researchers have dismissed animal rights activists as irrational (Herzog, 1990; Ulrich, 1991), anti-intellectual, anti-science and misanthropic (Nicoll & Russell, 1990) and question the priority that has been placed on animal research (Caplan, 1983). Nicoll and Russell (1990) contend that of all of the animals that are consumed in the United States, 0.3% are used for research and teaching and that these activities receive almost two-thirds of the criticism of animal rights writers. The scientific community has responded under growing criticism and pressure, asserting that animal research has and will continue to reduce human suffering and death (Gallup & Suarez, 1987; Miller; 1985) and that there are no adequate alternative methods of research at this time (Feeney, 1987; Perkins, 1990). Organizations such as the National Association for Biomedical Research and the Incurably 111 for Animal Research have been formed to lobby on behalf of researchers and to educate the public about research issues (Lutherer & Simon, 1992; Vaughan, 1988).

    While many researchers are defending the continued use of animals in research, others have begun to question the value and moral legitimacy of using animals as research subjects. Takooshian (cited in Grodsky, 1983) found that researchers had mixed feelings about animal-based research. The debate has been staged in letters to the editors of scholarly journals (see Lansdell, 1986; Moriarity & Alien, 1986; Rollin, 1986). William K. Estes (1991), editor at Psychological Science, characterized the animal rights issue as "dividing the readership" (p. 202). Interest in animal rights issues has resulted in the creation of new journals dedicated to scholarship on the subject of our relationship with nonhuman animals (i.e., Ethics and Animals, International Journal for the Study of Animal Problems, Anthrozoös) and a plethora of symposia on the subject (Burghardt & Herzog, 1980).

    Increased sensitivity to animal issues has led to the development of guidelines governing the use of animals in research in many disciplines (e.g. APA, 1985; National Institutes of Health, 1978) which includes the establishment of Animal Research Committees to evaluate and approve research using animal subjects and regulations onthe care of these animals. The costs of such care are high and have put financial pressure on many animal research models (Barnes, 1986; Viney, King, & Brendt, 1990). Hineline (1986) supports the APA guidelines as a rapid, more flexible and less disruptive means of ensuring humane treatment than would be available under a legislative approach.

    Some psychologists have called for more extensive guidelines and better adherence to the existing guidelines. Kelly (1986) stated that animal use committees rubber stamp proposals rather than act as "vigilant animal welfare advocates" (p. 841). Criticism from within psychology has focused on reduction of the number of animal subjects (Ulrich, 1991), improved living conditions of subjects, more humane procedures, replacement of animal models with alternative methods such as computer models, tissue and organ cultures, and chemical analyses (Bowd, 1980), and ensuring that research is meaningful and not redundant (Mikhail, Kamaya, & Glavin, 1979). Psychologists working toward the realization of such goals have organized to form the Psychologists for the Ethical Treatment of Animals (PsyETA).

    Many psychologists concerned with the rise of anti-animal research sentiment have advocated educating the public about the benefits of animal-based research (Nicoll & Russell, 1990; Vaughan, 1988). However, in a study of the responsiveness and quality of information provided by research organizations and animal rights organizations, Johnson and Morris (1987) found that animal rights groups were much quicker to respond and that the quality of their communication materials was much higher than that of the research organizations. Much of what the research organizations sent was insubstantial or irrelevant. Nicoll and Russell (1990) have called for increased funding of pro-research , foundations to improve education initiatives.

Philosophical Arguments

    Recently, psychologists have begun to research the underlying motivations of animal rights activism. Many researchers believe that a clear understanding of the philosophical arguments of animal rights is essential in order to defend adequately animal-based research (Herzog, 1990; Lutherer & Simon, 1992; Ulrich, 1991). Many philosophers have been prolific on the subject of the moral status of animals. The two most influential are Australian professor Peter Singer and North Carolina State University professor Tom Regan (Garner, 1993; Herzog, 1990). These and other philosophers have served as the "midwives" of the modern animal rights movement (Jasper & Nelkin, 1992, p. 90), articulating the beliefs of the activists and providing the intellectual basis of the movement..

    In Animal Liberation (1975), Peter Singer based his assertion of animal rights in the moral ethics of utilitarianism. The first part of Singer's argument is that any sentient creature, one that can experience pleasure and pain, has an interest in minimizing suffering and maximizing pleasure. Singer then, following the basic principle of equality, maintains that the interests of every creature affected by an action should be taken in to account and given the same weight as the interests of any other being. Singer states that nonhuman animals above the phylogenetic level of the oyster are capable of experiencing pain. Therefore, these animals should be given equal consideration of interests. Human use of animals for food, clothing, research subjects, and entertainment leads to their suffering thus violating the principle of equality, and exhibits speciesism, a term coined by Ryder (1975), which Singer (1975) defines as "a prejudice or attitude of bias toward the interests of members of one's own species and against those of the members of another species" (p. 7).

    In The Case for Animal Rights, Regan (1983) espouses the "rights" argument. He asserts that all "subjects of a life," those who experience consciousness (i.e. have beliefs, desires, perception, memory, a sense of the future, an emotional life including feelings of pleasure and pain, preferences, and the ability to initiate action in the pursuit of goals) have inherent value. Furthermore, all who have inherent value have it in equal measure and are accorded the right to respectful treatment. Regan asserts that animals meet the criteria of inherent value, and, therefore, have the right to be respected and not to be harmed. Regan acknowledges that some animals seem to lack many of the attributes of consciousness. However, in the absence of definitive evidence of lack of consciousness, one should assume that animals are indeed conscious and worthy of respectful treatment.

    Regan contends that humans view animals as renewable resources rather than subjects of a life and calls for the immediate and total abolishment of institutionalized animal exploitation including the use of animals in scientific research. Rollin (1985), another proponent of the rights argument, believes that "to expect the elimination of animal research is Utopian" (p. 924) but that the interests and rights of research animals should be maximized to the extent allowed by the goals of the research.

    Philip (1986) believes that the animal rights debate cannot be resolved in a reasoned, scholarly manner as philosophers have asserted. Herzog (1990) also doubts the influence of philosophy as a determinant of ethical decision making, contending that emotional factors may have a more primary influence. Robinson (1990) found the philosophical arguments compelling enough to bring about closure of a university vivarium.

Characteristics of Animal Rights Activists

    In addition to studying the philosophical arguments of the animal rights movement, researchers have begun to study the animal rights activists themselves. Activists are primarily young (Jasper & Nelkin, 1992; Kaplan & Herzog, 1991; Plous, 1991), nonreligious, from urban or suburban areas (Jasper & Nelkin, 1991; Kaplan & Herzog, 1991), white (Kaplan & Herzog, 1991; Plous, 1991); and well-educated. More than half of all activists have college degrees (Jasper & Nelkin, 1992).

    Most, but not all, activists do not eat meat or buy leather products. About 20-25% are vegan, consuming no animal products whatsoever (including eggs and milk) and about half are vegetarian, consuming no meat, poultry, or seafood (Kaplan & Herzog, 1991; j Plous, 1991). In Plous's (1991) survey of activists, 78% said that they value human and nonhuman life equally; 7% valued nonhuman life higher than human life.

     Studies (Jamison & Lunch, 1992; Kaplan & Herzog, 1991; Plous, 1991; Sperling, 1988) have also shown that the movement is comprised principally of women. Sixty to seventy percent of animal protectionists are women (Jasper & Nelkin, 1991). Plous (1991) found that female animal rights activists were more involved in the movement and have stronger views, being more likely than men to value nonhuman life more than humanlife, favor break-ins, and to be vegan or vegetarians.  Animal rightists have a different moral ideology than the general population. Kaplan and Herzog (1991) found that the majority of the activists they studied were "Absolutists." This type of ethical decision making is characterized by belief in universal moral principles and the corresponding conviction that adherence to them will invariably lead to positive outcomes. The researchers concluded that this ideology may make animal rightists less willing to compromise with those who do not agree with their views. They also believe that while this moral orientation may attract some to the movement, it may deter others from taking part.

    Herzog (1993) conducted interviews with 23 "rank-and-file" activists and illuminated the diversity of the individuals which comprise the movement. Some individuals joined the movement as a result of analyzing the philosophical arguments, others were motivated by emotion, some advocated civil disobedience and many felt morally superior to nonactivists. Herzog noted that the most consistent characteristic among the activists interviewed was the degree to which the movement had become the central focus of their lives. He compared the activists' involvement with the movement to religious conversion citing 1) the change in fundamental beliefs, 2) subsequent changes in lifestyle, 3) the need to spread the message to others, 4) the sense of sin for the world's injustice to nonhuman animals, and 5) moral righteousness.

Attitudes of the General Public Towards the Use of Animals

    Research on the general public has shown that the widespread media attention to animal rights issues has not changed the attitudes of most people toward traditional uses of animals. The majority of Americans are not opposed the use of animals as research subjects (Driscoll, 1992) but are concerned that animals be treated humanely (Gallup & Beckstead, 1988; Sieber, 1986). Gallup & Beckstead (1988) found that only 11.4% of the college students who responded to their questionnaire had ever seriously considered becoming a vegetarian in an effort to save animal lives. Respondents of Driscoll's (1992) study were opposed to use of animals in luxury garments or as subjects in product testing research. The study did not, however, assess whether their behavior corresponded to these attitudes.

    Attitudes and behavior on animal welfare issues are often inconsistent. While 76% of Gallup & Beckstead's respondents indicated that they were very concerned about pain and suffering in animals, 67% indicated that new surgical procedures and experimental drugs should be tested on animals before being used on humans. Braithwaite and Braithwaite (1982) found that the majority of their questionnaire respondents disapproved offeree feeding geese in order to enlarge their livers for pate, but approved of eating pate produced by force-fed geese.

    Attitudes of the general public towards the use of animals for human gain vary across college major, religious affiliation, pet ownership, age, and gender. Humanities majors are more likely than social or natural science majors to disapprove of animal-based research (Gallup & Beckstead, 1988). Individuals with no religious affiliation or  affiliation with theologically liberal groups (Bowd & Bowd, 1989), pet-owners, and young people (Driscoll, 1992) are especially likely to be concerned about the treatment of animals.

    Women are more likely than men to be concerned about the pain and suffering of animals, less likely to approve of animal-based research (Driscoll, 1992; Gallup  Beckstead, 1988; Kellert & Berry, 1987), and more likely to refuse to shock an animal as a part of a hypothetical experiment (Tennov, 1980). Herzog, Betchart, and Pittman (1991) found that feminine sex role orientation as measured by the Bern Sex Role Inventory is positively correlated with concern for the well being of other species, but that only about 10% of the variance in attitudes towards animal welfare was accounted for by gender and sex role orientation.

Sources of Variance in Attitudes Towards the Use of Animals

    Takooshian (cited in Grodsky, 1983) found that attitudes toward animal-based research are associated with attitudes towards animals in general. It is intuitive to assert that attitudes toward animals may influence to some degree attitudes toward how they ought to be treated. To research attitudes towards a wide variety of wild animal species, Kellert and Berry (1987) interviewed over two thousand Americans. Their study revealed the presence of a variety of basic attitudes towards animals and found that men and women differed significantly in their attitudes. The differences in attitudes were "so pronounced as to suggest that gender is among the most important demographic influences on attitudes towards animals in our society" (p. 365).

    Women scored significantly higher than men on the humanistic and moralistic attitude scales. The humanistic attitude is characterized by feelings of strong affection and attachment to individual animals (usually pets), wild animals that are phylogenetically close to humans, and large and aesthetically attractive species. Accompanying this perspective is empathy for animal emotion and thought, which often leads to anthropomorphism, the attribution of human characteristics to animals (Kellert, 1988).

    The primary characteristic of the moralistic attitude is a strong philosophical concern for how humans treat animals. Men were more likely than women to score highly on the utilitarian and dominionistic scales. The fundamental concerns of these attitudes are the practical and material value of animals and the derivation of personal satisfaction from the mastery and control of animals.

    Citing the research of Gilligan (1982), Kellert and Berry (1987) propose that the basis for the differences in attitudes lies in gender differences in moral development. Gilligan found that different socialization experiences produce significant differences in the moral and ethical perceptions of men and women. The female moral emphasis is on responsibility to others, caring and compassion, empathy, and nonaggressiveness. This moral viewpoint corresponds with Kellert and Berry's observation that women tend to exhibit strong emotional attachments to individual domestic animals and opposition to activities that are perceived as harmful to animals. Men are principally concerned with personal autonomy, hierarchy, assertiveness and individual rights. These values are congruent with the tendency to derive satisfaction from the exploitation and mastery of animals.  Kellert and Berry (1987) also gathered data on preferences towards different species of animals. A qualitative analysis of the ratings (Kellert, 1988) revealed 12 factors that appear to be important in public preference toward various species. These factors are size, aesthetics, intelligence (the capacity for reason as well as feeling and emotion), dangerousness, likelihood of inflicting property damage, predatory tendencies,  phylogenetic relatedness to humans, cultural and historical relationship, relationship to human society (e.g., pet, domestic farm, game, pest, native wildlife, exotic wildlife), texture (the more unfamiliar, the less preferred), mode of locomotion, and economic value of the species.

    Burghardt and Herzog (1980) propose 26 factors that are important in making ethical judgments about a given use of an animal. The factors are grouped into four categories: human benefits, anthropomorphism, ecology and psychology. Factors in the human benefits category are food, clothing, transportation, recreation, research, pests and  competitors, danger and disease, and domestication. Ethical judgments resulting from the first five factors vary widely and represent the major areas of interest for animal rights activists. In general, labeling a species as a "pest" or perceiving a species as being dangerous to human well being removes much of the stigma of killing it (see also Herzog, 1988). Use of domesticated animals is generally more acceptable than use of wild  animals. Use of these animals is often justified because "they were put here for our use" or "wouldn't exist without us" (p. 765). The researchers also cite the public's unfamiliarity of intensive farming and slaughtering techniques as contributing to the acceptance of use of these animals.

    Factors in the anthropomorphism category are pain and suffering, goriness, phylogenetic similarity, humanoid appearance, mental similarity, cuteness, size, longevity, and disgusting habits. Killing or use of an animal is considered more acceptable if it minimizes the perceived pain and suffering of the animal. Correspondingly, if the use of an animal is deemed "gory" by observers it will be judged less acceptable. Burghardt and Herzog point out that philosopher Peter Singer might not find eating raw (live) oysters acceptable if they screamed and bled upon being chewed.  Phylogenetic similarity, humanoid appearance, perceived mental similarity, cuteness, large size, and longevity result in more favorable treatment by humans. On the other hand, animals that engage in behavior that violates humans' "anthropocentric" (p. 766) and culturally-determined sense of decency (e.g. vultures, hyenas, rats) are deemed less worthy of favorable treatment by humans.

    The factors under the ecology category are rarity, diversity, and ecological balance. Rare species have more intrinsic worth than those that are common. Burghardt and Herzog consider diversity and ecological balance to be readily appreciated but seldom considered by the general public.

    Habituation, aesthetics, individual variability, behavioral plasticity, "call of the wild," and spiritual and religious factors comprise the psychology category. Repeated exposure to acts that are initially viewed as being cruel such as slaughtering a farm animal or sacrificing a lab animal eventually lead to desensitization and gradual acceptance of such treatment. Beautiful animals are entitled to better treatment than ugly ones. Species in which humans perceive individual members to vary in behavior or morphology and that demonstrate a higher degree of behavioral plasticity and adaptability are more favorable. Appreciation of the wild results in higher ethical value of wild animals. Religious or spiritual influences may have a positive or negative influence on human judgments about animals.

    Many studies have shown the influence of these preference factors on attitudes towards the treatment of animals. While support for use of animals in research is generally acceptable, use of animals of "higher" phylogenetic status is regarded as less acceptable than use of "lower" species (Braithwaite & Braithwaite, 1982; Burghardt & Herzog, 1980; Driscoll, 1992; Kellert & Berry, 1987; Plous, 1991). Also, public approval of protection of endangered species is greater for phylogenetically "higher" species than for those that are "lower." It is apparent that some animals have higher moral value than others.

    Plous (1993) found perceived biological similarity to be an important factor in explaining variance in attitudes towards the treatments of animals. She based her research on the hypothesis that behavior towards nonhuman species follows the "similarity principle" which states that "in general, people give more consideration to others who are perceived as similar to themselves than to those who are perceived as dissimilar" (p. 32). This principle has been shown to have substantial influence on humans' interactions with other humans. For example, people are more likely to help others of the same race (Crosby, Bromley, & Saxe, 1980), similar appearance (Emswiller, Deaux, & Willits, 1971; Graf & Riddell, 1972), political views (Karabenick, Lerner & Beecher, 1973), and nationality (Feldman, 1968).

    In a series of studies, Plous consistently found that humans' concern for other animals correlated highly with perceived similarity to humans. Plous found that priorities for protecting endangered species and physiological reactions to witnessing animal abuse correlated highly with the species' biological similarity to humans. Ratings of anatomical, intellectual and emotional similarity explained 53% of the variance in ratings of concern for animals.

    Perceived biological similarity was also closely related to perceptions of how capable animals are of experiencing pain. However, Plous found that animal rights activists rated animals' capacity for pain much higher than nonactivists and that, because activists believe that almost all animals experience pain, their similarity ratings did not correlate significantly with pain ratings.

    Eddy, Gallup, and Povinelli (1993) found that perceptions of biological and mental similarity of animal species are closely associated with phylogenetic group membership. More importantly, they found that perceptions of similarity correlate highly with attributions of cognitive processes in other species. They also found that dogs and cats were attributed higher cognitive capabilities than were mammals in general. These findings led the researchers to conclude that peoples' attributions of similarity of conscious experience and cognitive abilities may be based in part on the degree to which they have formed an attachment bond with the particular species of animals.

    Thus, research has shown that perceived similarity has a tremendous effect on our ;perceptions of and concern for different animal species. It is the purpose of this thesis to determine whether perceptions of similarity in terms of capacity to experience consciousness correlate with beliefs about whether animals should be granted rights equal to those of humans. It is hypothesized that individuals who believe that animals are similar to humans, have the capacity for reason and the ability to experience emotion will be more likely to believe that animals should be granted the right to live their lives free from human intervention.



    Participants were 205 female and 79 male undergraduate students enrolled in psychology classes at a large regional state university in North Carolina. The students volunteered for participation in the study in return for extra credit.


    Attitudes toward human-nonhuman similarity and animal consciousness were measured by seven 5-point Likert-scale statements. Attitudes toward animal rights were measured by three Likert-scale statements and a single item pertaining to affiliation with one or more animal rights organization(s). These 11 items were part of a 69-item questionnaire designed to measure a variety of attitudes such as those toward the use of animals in research, the value of science, and misanthropy. The questionnaire included the 14 statements concerning animal research used by Gallup and Beckstead (1988) in their survey of college students. An additional ten items elicited demographic data and information on past and current activism.

    Preliminary factor analysis was performed on a priori sets of items expected to be associated with attitudes towards animal rights and similarity beliefs.  Items with low loadings in the factor analysis and low item-total correlation were dropped from use in this study.

    The similarity items. The seven similarity items are listed below.

1.   Humans are not the only creatures who have thoughts; some animals can think too. (THINK)

2.   Some animals have emotions such as affection, anger, or fear. (EMOTION)

3.   Humans are so vastly different from other life forms that it is a mistake to classify humans as being animals. (DIFFERENT)

4.   Humans evolved from other animals, thus other animals must be structurally and mentally similar to humans. (EVOLVED-SIMILAR)

5.   Humans are very similar to other animals. (SIMILAR)

6.   A dog or a cat may act as if it is emotional, but it doesn't really feel emotions like humans do. (NO EMOTION)

7.   It is ridiculous to suppose that a cat or a dog can think. (NO THINK)

    The rights items. The four rights items are listed below.

8.   Humans have no right to displace wild animals by converting wilderness areas into farmland, cities, and other things designed for people. (DEVELOPMENT)

9.   Animals should be granted the same rights as humans. (RIGHTS)

10. Having extended basic rights to minorities and women, it is now time to extend them also to animals. (CIVIL RIGHTS)

11. Do you belong to any groups whose primary concern is the protection of the rights of nonhuman animals? (GROUP)


    The questionnaire was administered to participants who were instructed to indicate whether they strongly disagree, disagree, have no opinion or are neutral, agree, or strongly agree with each statement, and to choose the appropriate responses to the multiple choice items. Students were notified verbally and in writing that their responses would be confidential. Questionnaires were completed in a classroom setting in the presence of an investigator and returned immediately upon completion.


    Frequency distributions of the responses to the similarity and rights items appear in Appendix A. Fifteen percent of the participants agreed with the rights statement "Animals should be granted the same rights as humans." This statement was originally used by Gallup and Beckstead (1988) in their survey of State University of New York at Albany students. Chi-square analysis revealed that the responses of the SUNY students did not differ significantly from those of the eastern North Carolina students surveyed in this study, c2 (4, N = 547) = 5.273, p = .260.

    Canonical correlation analysis was performed between the sets of similarity variables and rights variables to assess the relationship between the two groups of variables. Prior to performing the analysis, logarithmic transformations were applied to variables 1    ' (THINK), 2 (EMOTION), 6 (NO EMOTION), and 7 (NO THINK) to reduce skewness of their distributions. The distributions of THINK and EMOTION, which were negatively skewed, were reflected prior to the logarithmic transformation and will therefore be referred to as (NO) THINK and (NO) EMOTION.

    Four pairs of canonical variates were extracted from the data. The first canonical correlation was .464 which is larger than any of the between-set simple correlations. (The complete correlation matrix is shown in Appendix B.) The first correlation was significant, F(28, 986) = 3.84, p < .0001. The second canonical correlation was .27 and also significant, F(18, 775) = 2.05, p = .006. With the first two canonical correlations removed, the remaining two correlations were not statistically significant, F(10, 550) = 1.51, p = .13.

    Statistics on the first two pairs of canonical variates appear in Tables 1 and 2. Presented in Table 1 are the loadings (correlations between the variables and their canonical variates), the canonical correlations, and squared canonical correlations (percentage of variance shared by the two canonical variates). Canonical redundancy statistics are shown in Table 2. The percentage of variance shared by the canonical variates reveals that the first pair was strongly related while the second pair was only minimally related.

    The first similarity canonical variate loaded heavily on all of the variables in the similarity set. The largest correlations were with SIMILAR, NO THINK and (NO) THINK, .781, -.692, and -.640, respectively. The smallest loading was with DIFFERENT, -.424. The first Similarity canonical variate extracted 35.0% of the total variance in the similarity variables. Similarly, the first rights canonical variate loaded well on each of the variables in its set. The largest correlations were with CIVIL RIGHTS and RIGHTS, .929 and .829, respectively; the smallest was with DEVELOPMENT, .399. This canonical variate accounted for 49.0% of the total variance in the rights variables. The first pair of canonical variates indicates that the belief that animals are similar to humans, can think and experience emotion is positively related with the belief that animals should have rights.

     Redundancy analysis results show that percentage of variance among the variables in each set that is explained by the canonical variate of the opposite set is rather small. The proportion of variance among the similarity variables that is explained by the rights canonical variate is 7.5%. The proportion of rights variance that is explained by the similarity canonical variate is 10.6%.

    With a threshold loading of .3, the second similarity canonical variate loaded negatively on (NO) THINK, and positively on DIFFERENT and NO EMOTION. The second rights canonical variate loaded very heavily and negatively on DEVELOPMENT and positively on GROUP. Sensible interpretation of the second pair of canonical variates was not possible. It is notable that the percentage of variance shared by the second canonical variates is trivially small (7.4%), as are their redundancies.

     The relationship between perceived consciousness in nonhuman animals and attitudes toward animal rights was also examined by creating composite scores on the similarity and rights items for each respondent and calculating the Pearson correlation coefficient between the rights composite score and the similarity composite score. The composites were derived by summing the numerical values of the responses to each of the items. The values ranged from one for "strongly disagree" to five for "strongly agree." Values for DIFFERENT, NO EMOTION, and NO THINK were reflected by subtracting each from six before summing. The resulting distributions of composite scores for both similarity and rights items were approximately normal.

     The correlation between the similarity and rights composites was significant, r = .416, p < .0001. Though the relationship was significant, only 17.3% of the variability in the responses to the rights items was explained by the linear relationship between the rights items and the similarity items.

     Reliability of the similarity and rights composites was estimated using Cronbach's coefficient alpha. For the similarity items, alpha = .703; for the rights items alpha = .666. The coefficients reflect a moderately high degree of self-consistency among the items in each set.



    Though the number of animal rights organizations and their memberships have been growing, and in spite of the widespread publicity of animal rights issues through a myriad of media, only fifteen percent of the students in this study believed that animals should have the same rights as humans. This finding is not unique to this geographic area as it is consistent with the results of Gallup and Beckstead's (1988) study of attitudes among students at a New York state-based university. The low support for animal rights found in this study supports Herzog's (1995) assertion that public interest in animal rights may be waning.

    In addition to providing data on the prevalence of support for animal rights, this study has contributed to the growing body of knowledge on factors that influence attitudes toward the treatment of animals. Examined here was the hypothesized association between perceived similarity between humans and animals and support for animal rights. While many studies have examined psychological correlates of concern for animals, this study examines correlates of support for equal rights between humans and animals.

    Perceived similarity between animals and humans was moderately positively correlated with support for animal rights. The correlation between the similarity and rights composite scores was .416. Perceived similarity explained 17.3% of the variance in support for animal rights.  Canonical correlation analysis also revealed that a reliable relationship exists between beliefs about human-nonhuman animal similarity and attitudes toward animal rights. The first canonical correlation was the only one of the four pairs of canonical variates produced by the analysis that accounted for more than a trivial degree of shared variance between the sets of canonical variates. Analysis of the loadings of the first pair of canonical variates illuminated an equity dimension underlying the relationship between attributions of similarity and support for animal rights - an "equal rights for equal beings" dimension. The similarity canonical variate explained 11% of the variance in the rights canonical variate in this dimension. People who perceive animals as being very similar to humans and having the ability to think and to experience emotion are more likely than those who do not to support the extension of rights to animals.

    S. Plous (1993) conducted similar research to determine the extent to which the "similarity principle" influences peoples' concern for animals. The similarity principle states that "in general, people give more consideration to others who are perceived as similar to themselves than to those who are perceived as dissimilar" (p. 32). Plous found that perceived biological similarity between animals and humans correlated well with ; peoples'concern for animals.

    In the equity dimension underlying the relationship between perceptions of similarity and support for animal rights, positive beliefs regarding the general similarity between humans and animals were weighted more heavily than attributions of cognitive capacity and emotional capacity, respectively. Responses to the similarity items revealed that the majority of the participants believed that nonhuman animals can experience emotion (90%) and think (74%). However, only about half agreed with the concept of animals being similar to humans. Twenty-six percent of the participants believed that humans are so vastly different from animals that they should not be classified as animals. Even though the participants ascribed mental abilities to animals, many did not believe that humans and animals are similar.

    This implies that 1) there may be qualitative differences in the mental capabilities attributed to animals and those attributed to humans - animals may be perceived as being capable of limited, relatively unsophisticated mental processes but not those similar to humans, and 2) emotional capacity may not be as important as cognitive capacity in attributions of similarity.

    Variation in people's willingness to attribute different degrees of consciousness to animals has actually been well documented. People have been found to be more willing to attribute the capacity for emotion in animals than the capacity for cognition (Burghardt, 1985; Herzog & Galvin, in press; Rasmussen, Rajecki and Craft, 1993.) Herzog and Galvin (in press) found that attributions of human-like pain and suffering in animals were more common than attributions of more complex forms of consciousness such as human­like emotion, affection to man, and reason, respectively. The researchers found three dimensions underlying individual differences in participants' attributions of mental states in animals: 1) an affective dimension, associated with how the participants felt about the animals, 2) a sentience dimension, associated with pain, suffering, and moral consideration, and 3) a cognitive dimension, associated with capacity for higher mental processes. The affective and sentience dimensions correlated with concern for animals, but, interestingly, the cognitive factor did not. The fact that moral consideration formed a common factor with pain and suffering led the researchers to speculate that the finding provides "a psychological analog to Singer's (1975) belief that moral status ultimately rests on the capacity for sentience" (p. 12 of manuscript).

    Attributions of mental states also vary across animal species, generally corresponding with phylogenetic status (Eddy et al., 1993, Herzog & Galvin, in press; Rasmussen et al., 1993). Invertebrates are believed to have the lowest level of mental capacity followed by non-mammalian vertebrates and mammals, respectively. Furthermore, Eddy et al. (1993) found that attributions of species' mental functioning were positively correlated with perceptions of similarity to humans and human experience.

    To summarize, attributions of mentation in animals vary with type of mentation and with the phylogenetic status of the animal species. Species that are perceived to be similar to humans are judged to have more sophisticated mental capabilities than those that are not. Perceived similarity has also been shown here to be associated with support for animal rights.

    Plous (1993) found species-based variation in the perception of biological similarity between humans and animals among a group of animal rights supporters. This appears to be counter to the results presented here which imply that animal rights supporters would perceive most species to be very similar to humans. However, the animal rights supporters generally rated the various animal species as being more similar to humans than did non-supporters. The study also showed that among the animal rights supporters, there was no correlation between perceived biological similarity and attributions of ability to experience pain, because the activists tended to believe that all animal species possess a large capacity for pain.

    A great deal of ethological research has been conducted to determine whether animals have various mental abilities and the extent to which they compare to human mental capacities (see Griffin, 1992). Many researchers expect the findings of these studies to be influential in the campaign toward establishing rights for animals. For example, Rasmussen et al. (1993) stated that "much of the current debate about animal welfare and rights ... hinges on arguments about the mental states of animals (p.284)." Furthermore, the basis of philosopher Tom Regan's argument for granting rights to animals is that they are capable of experiencing mental states (and therefore have inherent value, and therefore should be afforded rights).

    Research has established that scientific evidence of consciousness in animals is not necessary for humans to formulate beliefs about animal mentality. People take a common sense approach in formulating their beliefs about consciousness in animals. Eddy et al. (1993), Rasmussen et al. (1993) and Sanders (1993) have documented these "folk" perceptions of animal mentality. These attributions of mentality have also been measured here and have indeed been shown to be related to support for animal rights, thus to some extent justifying claims that establishment of evidence of mental abilities in animals will lead humans to conclude that they should be afforded the right to live their lives free from human intervention.  However, the relationship between perceptions of mental similarity between humans and animals is not particularly strong. In the canonical correlation analysis, the percentage of overlap between the first two canonical variates was only 21.5%. From the analysis of composites, it was found that only 17.3% of the variance in attitudes towards animal rights was attributable to similarity ratings.

    More research should be conducted to elucidate the psychological underpinnings of support for animal rights. The author recommends that research be conducted on the extent to which various personality factors such as capacity for empathy, comfort with sacrifice and propensity for martyrdom are associated with support for animal rights. These are variables that may be more closely associated with actual behavior versus attitudes. As Braithwaite and Braithwaite (1982) showed, stated support for animal rights may not be at all congruent with actual animal use-related behaviors.


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